The objective of the proposed research is the study of neuropeptide containing amacrine cells within the turtle retina. I will use indirect fluorescence and peroxidase immunocytochemical techniques at the light microscopic level to determine the following for each type of neuropeptide containing amacrine cell studied: amacrine cell density and distribution within the retina; the shape of amacrine cell dendritic arbors and cell bodies; and the distribution of amacrine dendrites within subdivisions of the inner plexiform layer. A combination of immunoperoxidase and Golgi techniques will be used in ultrastructural studies to determine the kinds of retinal neurons amacrine cells synaptically contact, and in which subdivisions of the inner plexiform layer these contacts are made. I will also help determine the subcellular storage sites of neuropeptides within retinal amacrine cells and whether or not neuropeptides can co-occur with other neurotransmitters. My studies will expand our knowledge of the role of neuropeptides and amacrine cells in visual processing and provide a sound morphological basis for biochemical and physiological studies of other workers.